1. Field of the Invention
This invention relates to a method and an apparatus for multinominal continuous analysis for raising multinominal reactions on a reaction line and analyzing the reactions.
2. Description of the Related Art
In an automatic continuous multinominal analyzer of discrete type, specimens to be analyzed and reagents for causing reaction with the specimens are supplied to reaction vessels. In general, since one reaction vessel corresponds to one item of analysis, the specimens are distributed to a plurality of reaction vessels to perform a plurality of items of analysis. The reaction vessels are arranged circumferentially and transferred intermittently to a reagent distributing position.
A plurality of reagent vessels containing reagents are positioned near the reagent distributing position.
The reagents in the reagent vessels are extracted by a suction tube and discharged to the reaction vessels by a discharge tube. Extraction and discharge operation is performed by a syringe. A common tube serving as a suction path and a discharge path for the syringe is selectively connected to the suction tube or the discharge tube by a switch valve.
When a reagent is to be extracted, the common tube is connected to the suction tube. A reagent of an amount necessary to the analysis is extracted by the suction operation of the syringe through the suction tube to the syringe.
Then, the common tube is connected to the discharge tube. The reagent is distributed to the reaction tubes through the discharge tube by the discharge operation of the syringe.
The degree of reaction of a specimen is detected as a density or an activation value by optically detecting the reacted specimen, when, for example, a color development reaction occurs.
In analysis by using an automatic analyzer of this type, generally, two reagents are used to analyze one item. Accordingly, reagents of the number twice the number of items of analysis are required. For example, if the number of items of analysis is twenty, forty kinds of reagents must be used. Hence, as the number of items of analysis is increased, the number of the reagent vessels is also increased; for example, several tens of reagents must be supplied to the automatic analyzer, and the management of the reagents is inevitably complicated. This is a disadvantage of the apparatus of this type.
The above-described automatic analyzer has another disadvantage that it is substantially impossible to exchange all the vessels at a time, since the amount of distribution varies depending on the item of analysis due to the variety of sizes of the reaction vessels. Therefore, the residual amounts of all of the reagents must be detected prior to an analysis.
The above-described automatic analyzer apparatus has still another disadvantage that, if the reagent in a reagent vessel is undesirably decreased to a little or nothing during an analysis, the common tube or suction tube may draw air, with the result that the reagent cannot be accurately distributed by the discharge tube. In addition, since a so-called drip-drip (the state that the discharge tube intermittently drips the reagent) occurs, results of the other items of analysis may be adversely affected. Further, if the outer surface of a reaction tube is contaminated, the reaction tube must be removed from the automatic analysis apparatus and cleaned prior to reanalysis, which may be required if analysis data is abnormal.